Productivity apps running on android supply from Bulgaria

We are a SW company owning productivity apps running on Android..
Our Main app OfficeSuite lets you easily view, edit, and create Word, Excel, and PowerPoint documents, and perform advanced PDF operations. Complete with our integrated file manager, this is the most feature-rich mobile office solution available on Android, iOS and Windows PC. We are looking for manufacturers of Android and windows PC devices and we would like to preload our App on their devices.